openspaceman

Beau is being too modest, he has designed and built a simple retort that makes charcoal from these loggettes in less than an hour plus a neat handling system for the barrels.

hardwoods bone dry are about 18.6 MJ/kg lower heating value, softwoods a bit more, this is about 5.2kWh(t), at 20% mc wwb this would only have 4.13 kWh(t) potential energy but would also have to boil off 200 grams of water. I think we should really work in higher heating values and then work out total losses as steam in the exhaust. As an old chemist once told me wood is a good energy source but a poor fuel. I gave up reading as soon as I saw he didn't know the difference between power and energy.

In which case you will burn a similar amount of energy in oil. As I said earlier energy released has to be accounted for, it either goes up the chimney as hot smoke, remains in ash pan as unburnt fuel or it enters the room and is dissipated through roof, walls, floor, windows and vents. In point of fact if the glass blackens the combustion is incomplete which means chemical energy is lost as carbon monoxide and other PICs and of course a decent gas or oil condensing boiler will have a flue gas temperature of less than 100C whereas not many stoves will be lower than 200C which represents a significant loss even with a clean burn.

Bill it's a bit difficult to know how the circuit should work with the manual pump but if I were doing this I would have a shuttle valve taking flow from the electric pump or the manual one. If the electric pump is not running then oil from the manual pump would push the valve over and then on to the spool block, if the no lever on the spool block was activated oil would simply return to tank. Normally the solenoid valve is activated by a switch which also starts the pump and allows oil to the ram. The brass plunger moves the spool and needs to be forcing the spool to the up position before you pump oil manually.

Yes it takes energy to boil the water off before the log will burn but it's not a large proportion of the energy in the log, the problem is more that it reduces the combustion temperature and the knock on effect of that is worse pollution given off. Even burning bone dry wood produces steam in the flue as the hydrogen in the wood turns to water. Comparing it with cement is very apples and oranges

That's efficiency of converting your labour into heat rather than the efficiency of converting chemical energy of the log into heat which we were discussing.

Whatever you do do not return this original to DVSA, they will lose some categories when you get a photo licence and you will have no proof. A mate lost his motorcycle entitlement this way.

Much more satisfaction and value added than firewood or charcoal

Isn't it past your bed time young man? It's the foot note in the document Well it looks like @donnk found there were, currently and for the purpose of your document they have been removed for someone taking the trailer (B+E) test after 2013 also I believe they are aware of the possibility and I don't think you will any longer be able to make use of it. For the current licences then B+E allows a vehicle up to 3.5 tonnes and a trailer up to 3.5 tonnes (with tacho if necessary but no O licence if trailer is less than 1020kg unladen) now as your document says you can gross 3.5 tonnes on the trailer axles, the super imposed load on the truck doesn't count. E.G. if you have a truck with 2tonne unladen weight and trailer with 1020 unladen weight then you can carry 1.5 tonne of weight of nose of trailer plus fuel and driver on the truck wheels plus the load on the trailer axles. Potentially this is a total payload of 3980kg including driver and equipment if you get the weight distribution right.

As you say air control , mostly preventing excess air being pulled from the room, heated and then sent up the chimney. This doesn't impact combustion efficiency but it does increase flue gas velocity so less likely for tars to settle out. The firebricks and baffles you mention are part of the way the stove design implements a couple of very simple concepts: The energy in the log is conserved after the combustion, so what goes into the room plus what goes up the chimney plus what is left in the ash are equal to the original energy that was in the log. The rules for good combustion are the three Ts, Time, Turbulence and Temperature Temperature: a high temperature allows all the products of combustion to burn out, any Products of Incomplete Combustion like smoke are caused by the flame being quenched before combustion is complete, apart from dangers to health they represent a loss of chemical energy up the chimney. A high combustion temperature is provided by the insulating effect of the firebricks. So the heat delivered to the room is through surfaces the combustion products heat after the combustion chamber and before going up the chimney. A flue temperature higher than necessary to prevent condensation in the chimney is wasted energy. This is why an insulated chimney is used. I don't have an insulated chimney as I like my flue gases to heat the brickwork as they are vented. I should insulate the top 4m length but it would not be cost effective for me. Some of the most efficient wood burners are masonry stoves which burn fast and hot and the heat then soaks out from the brickwork over the following hours. Time: A flame needs time to burn out, the baffle forces the burning flame to take a longer route and thus stay in the combustion chamber longer. Turbulence: jets of preheated air impinging on the flame mix the fuel gases and vapours together increasing the probability of meeting enough oxygen to completely burn the fuel. Then there is air to fuel metering, this is far more complicated than a fuel injector in a car but suffice to say the nearer to the correct ratio of fuel to air you can achieve (stoichiometry) the higher the temperature can be as you are no longer heating up air which then has a free ride up the chimney. With a petrol engine you can achieve pretty much a stoichiometric burn, with wood (and diesel actually) you always need more than stoichiometric air for a clean burn, this is known as excess air, it isn't used but it is needed to increase the probability of a fuel molecule being oxidised. Of course the other single big thing that depresses firebox temperature is moisture in the log.

I agree with most of that but swap "bit" for "very", also can never be as clean burning.

From your link: "American “5th wheel” type caravans are considered semi trailers and, as such cannot use an inertia (overrun) type braking system. The operation of the towing vehicle’s braking system must directly operate the brakes on the trailer and electrically controlled systems are permitted." " 1 In the case of a semitrailer or centre-axle trailer, the maximum mass to be considered for classifying the trailer corresponds to the static vertical load transmitted to the ground by the axle or axles of the semitrailer or centre-axle trailer when coupled to the towing vehicle and carrying its maximum load."

When i was in swansea a chap from port talbot came into A&E when I was there also, just the same, place was so busy a very butch junior doctor came into the waiting room, as the cubicles were full and she hooked it out with a needle from hypodermic, I was stunned, I expected a load of jelly to erupt from his eyeball,

You've got it, no different from a lot of enterprises that don't account for the external costs of their effluent or over-cropping.

I worked at Broomehall in 1974, They brought a tree surgeon in who was a fan of "Old Gravel guts" of Maggie May fame and he was raving about his latest album. I was his groundie on some oaks and it was the first time I'd been involved professionally with tree surgery. Although I had clambered around with a Danarm DDA110 at my girlfriends father's garden this was the first I saw of DDRT. Anyway it looks like he sold in the early 80s and I pulled his car out of Franks wood around 1983.

He was drinking a long way from Broomehall then, I recovered his car from woods below the landslip when his brother found it but never met the man himself, though I did work in the adjacent woodlands.

Yes you're right but sometimes I just cannot be bothered to read posts by certain people and the replies to them.

What a dilemma, do I ignore thread or killfile more of the posters who aren't on topic?

It's a strange one this, it's similar to the chap who got caught mowing the local recreation ground and then travelling back to the farm. If he had used DERV he may not have been fined but he could also have been done for using a tractor registered and having free road tax outside its use class.. So by putting DERV in it may be an admission that you are not using the tractor within it's licence class. Following on from that as you are not using it within agriculture use class then you have the various C&U regulations which you are no longer complying with. In the case of the farmer mowing the recreation ground, had he been returning along the road to his farm from a verge cutting job (excepted work), pulled into the recreation ground (off road though subject to road traffic act). proceeded to mow recreation ground with red diesel (excepted use). Then carried on verge mowing would he have been prosecuted? The main point is to always have a correct reason for where you are going if stopped and asked. In practice our tractor loloader combination never got stopped, despite being driven by a dopey hooligan and even used for household removals, I advised it was not lawful but the boss found it convenient and saved a fortune.

No I haven't written much but have alluded to it here over the years. It was a system originally intended for a charity making charcoal, as such it was holistic and made use of the fact that heat energy could be cascaded from a high temperature process (in our case running a gas turbine) and further downstream processes could utilise the lower temperatures, like drying and heating. A researcher I knew had been approached about his low temperature woodchip dryer by a firm needing to upgrade their slabwood to kindling. Realising his dryer would not be suitable he brokered a deal with our company to supply one. So the dryer we supplied was just a part of the system I envisaged, as such it had low efficiency and worse used gasoil but it enabled the client to turn 18tonnes of slabwood into £2500 of Tesco's packaged kindling in 24 hours. The client went on to increase capacity, become biomass powered and I believe the biggest supplier of kiln dried wood in UK.

Yes it is but this is one of the least windy places I know, probably not a very successful venture, even the water mills around heare are undershot so there would have been a dearth of power before steam.

Be careful when you open your eye in the morning, don't rush because the healing is easily torn.

Yes I think so, extract from FC bullettin 117: "Boards sawn from pine logs wet stored for 6 months quickly suffered surface defacement from moulds and sapstainers. However, very little defacement occurred in boards cut from logs stored for two to three years, probably because of the nutrient leaching associated with long-term water storage and the inhibitory action of bacteria which are abundant in wet stored wood. The porosity and strength of the timber of a range of species also altered during water storage; for both hardwoods and softwoods porosity increased signifi­ cantly, and the strength of softwood timbers reduced slightly although this did not reduce the yields of construction grade timber." There was a wind powered sawmill behind the house where I was born in this village, oddly the sails were fixed so only worked when the wind was SW, it had ceased working by the time I was born but my grandmother remembered it, the house on the spot is called Mill End.

...and remember the exemption on using a tacho no longer applies

That's your opinion, I was just stating a benefit of kiln drying. AFAIAC Logs for firewwood are a luxury good and their carbon footprint is in the same category as a flight to marbella. When we supplied a wood dryer there were no RHI payments and precious few kiln dried timber imports, in fact I suspect our customer kicked off the demand for the product. As the designer of the concept I was disappointed in the departure from the original plan to re use the heat from the process but the client had a view and that was to maximise profit and use of grant aid which were not compatible with my wishes. In terms of commercial success the clients were definitely right. They have a chinese view of capitalism and intellectual property.